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Diffstat (limited to 'assets/viz/2/goog/iter/iter.js')
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diff --git a/assets/viz/2/goog/iter/iter.js b/assets/viz/2/goog/iter/iter.js deleted file mode 100644 index 5bbb0bb..0000000 --- a/assets/viz/2/goog/iter/iter.js +++ /dev/null @@ -1,1284 +0,0 @@ -// Copyright 2007 The Closure Library Authors. All Rights Reserved. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS-IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -/** - * @fileoverview Python style iteration utilities. - * @author arv@google.com (Erik Arvidsson) - */ - - -goog.provide('goog.iter'); -goog.provide('goog.iter.Iterable'); -goog.provide('goog.iter.Iterator'); -goog.provide('goog.iter.StopIteration'); - -goog.require('goog.array'); -goog.require('goog.asserts'); -goog.require('goog.functions'); -goog.require('goog.math'); - - -/** - * @typedef {goog.iter.Iterator|{length:number}|{__iterator__}} - */ -goog.iter.Iterable; - - -/** - * Singleton Error object that is used to terminate iterations. - * @const {!Error} - */ -goog.iter.StopIteration = ('StopIteration' in goog.global) ? - // For script engines that support legacy iterators. - goog.global['StopIteration'] : - {message: 'StopIteration', stack: ''}; - - - -/** - * Class/interface for iterators. An iterator needs to implement a {@code next} - * method and it needs to throw a {@code goog.iter.StopIteration} when the - * iteration passes beyond the end. Iterators have no {@code hasNext} method. - * It is recommended to always use the helper functions to iterate over the - * iterator or in case you are only targeting JavaScript 1.7 for in loops. - * @constructor - * @template VALUE - */ -goog.iter.Iterator = function() {}; - - -/** - * Returns the next value of the iteration. This will throw the object - * {@see goog.iter#StopIteration} when the iteration passes the end. - * @return {VALUE} Any object or value. - */ -goog.iter.Iterator.prototype.next = function() { - throw goog.iter.StopIteration; -}; - - -/** - * Returns the {@code Iterator} object itself. This is used to implement - * the iterator protocol in JavaScript 1.7 - * @param {boolean=} opt_keys Whether to return the keys or values. Default is - * to only return the values. This is being used by the for-in loop (true) - * and the for-each-in loop (false). Even though the param gives a hint - * about what the iterator will return there is no guarantee that it will - * return the keys when true is passed. - * @return {!goog.iter.Iterator<VALUE>} The object itself. - */ -goog.iter.Iterator.prototype.__iterator__ = function(opt_keys) { - return this; -}; - - -/** - * Returns an iterator that knows how to iterate over the values in the object. - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable If the - * object is an iterator it will be returned as is. If the object has an - * {@code __iterator__} method that will be called to get the value - * iterator. If the object is an array-like object we create an iterator - * for that. - * @return {!goog.iter.Iterator<VALUE>} An iterator that knows how to iterate - * over the values in {@code iterable}. - * @template VALUE - */ -goog.iter.toIterator = function(iterable) { - if (iterable instanceof goog.iter.Iterator) { - return iterable; - } - if (typeof iterable.__iterator__ == 'function') { - return iterable.__iterator__(false); - } - if (goog.isArrayLike(iterable)) { - var i = 0; - var newIter = new goog.iter.Iterator; - newIter.next = function() { - while (true) { - if (i >= iterable.length) { - throw goog.iter.StopIteration; - } - // Don't include deleted elements. - if (!(i in iterable)) { - i++; - continue; - } - return iterable[i++]; - } - }; - return newIter; - } - - - // TODO(arv): Should we fall back on goog.structs.getValues()? - throw Error('Not implemented'); -}; - - -/** - * Calls a function for each element in the iterator with the element of the - * iterator passed as argument. - * - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * to iterate over. If the iterable is an object {@code toIterator} will be - * called on it. - * @param {function(this:THIS,VALUE,?,!goog.iter.Iterator<VALUE>)} f - * The function to call for every element. This function takes 3 arguments - * (the element, undefined, and the iterator) and the return value is - * irrelevant. The reason for passing undefined as the second argument is - * so that the same function can be used in {@see goog.array#forEach} as - * well as others. The third parameter is of type "number" for - * arraylike objects, undefined, otherwise. - * @param {THIS=} opt_obj The object to be used as the value of 'this' within - * {@code f}. - * @template THIS, VALUE - */ -goog.iter.forEach = function(iterable, f, opt_obj) { - if (goog.isArrayLike(iterable)) { - - try { - // NOTES: this passes the index number to the second parameter - // of the callback contrary to the documentation above. - goog.array.forEach( - /** @type {IArrayLike<?>} */ (iterable), f, opt_obj); - } catch (ex) { - if (ex !== goog.iter.StopIteration) { - throw ex; - } - } - } else { - iterable = goog.iter.toIterator(iterable); - - try { - while (true) { - f.call(opt_obj, iterable.next(), undefined, iterable); - } - } catch (ex) { - if (ex !== goog.iter.StopIteration) { - throw ex; - } - } - } -}; - - -/** - * Calls a function for every element in the iterator, and if the function - * returns true adds the element to a new iterator. - * - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * to iterate over. - * @param { - * function(this:THIS,VALUE,undefined,!goog.iter.Iterator<VALUE>):boolean} f - * The function to call for every element. This function takes 3 arguments - * (the element, undefined, and the iterator) and should return a boolean. - * If the return value is true the element will be included in the returned - * iterator. If it is false the element is not included. - * @param {THIS=} opt_obj The object to be used as the value of 'this' within - * {@code f}. - * @return {!goog.iter.Iterator<VALUE>} A new iterator in which only elements - * that passed the test are present. - * @template THIS, VALUE - */ -goog.iter.filter = function(iterable, f, opt_obj) { - var iterator = goog.iter.toIterator(iterable); - var newIter = new goog.iter.Iterator; - newIter.next = function() { - while (true) { - var val = iterator.next(); - if (f.call(opt_obj, val, undefined, iterator)) { - return val; - } - } - }; - return newIter; -}; - - -/** - * Calls a function for every element in the iterator, and if the function - * returns false adds the element to a new iterator. - * - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * to iterate over. - * @param { - * function(this:THIS,VALUE,undefined,!goog.iter.Iterator<VALUE>):boolean} f - * The function to call for every element. This function takes 3 arguments - * (the element, undefined, and the iterator) and should return a boolean. - * If the return value is false the element will be included in the returned - * iterator. If it is true the element is not included. - * @param {THIS=} opt_obj The object to be used as the value of 'this' within - * {@code f}. - * @return {!goog.iter.Iterator<VALUE>} A new iterator in which only elements - * that did not pass the test are present. - * @template THIS, VALUE - */ -goog.iter.filterFalse = function(iterable, f, opt_obj) { - return goog.iter.filter(iterable, goog.functions.not(f), opt_obj); -}; - - -/** - * Creates a new iterator that returns the values in a range. This function - * can take 1, 2 or 3 arguments: - * <pre> - * range(5) same as range(0, 5, 1) - * range(2, 5) same as range(2, 5, 1) - * </pre> - * - * @param {number} startOrStop The stop value if only one argument is provided. - * The start value if 2 or more arguments are provided. If only one - * argument is used the start value is 0. - * @param {number=} opt_stop The stop value. If left out then the first - * argument is used as the stop value. - * @param {number=} opt_step The number to increment with between each call to - * next. This can be negative. - * @return {!goog.iter.Iterator<number>} A new iterator that returns the values - * in the range. - */ -goog.iter.range = function(startOrStop, opt_stop, opt_step) { - var start = 0; - var stop = startOrStop; - var step = opt_step || 1; - if (arguments.length > 1) { - start = startOrStop; - stop = opt_stop; - } - if (step == 0) { - throw Error('Range step argument must not be zero'); - } - - var newIter = new goog.iter.Iterator; - newIter.next = function() { - if (step > 0 && start >= stop || step < 0 && start <= stop) { - throw goog.iter.StopIteration; - } - var rv = start; - start += step; - return rv; - }; - return newIter; -}; - - -/** - * Joins the values in a iterator with a delimiter. - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * to get the values from. - * @param {string} deliminator The text to put between the values. - * @return {string} The joined value string. - * @template VALUE - */ -goog.iter.join = function(iterable, deliminator) { - return goog.iter.toArray(iterable).join(deliminator); -}; - - -/** - * For every element in the iterator call a function and return a new iterator - * with that value. - * - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterator to iterate over. - * @param { - * function(this:THIS,VALUE,undefined,!goog.iter.Iterator<VALUE>):RESULT} f - * The function to call for every element. This function takes 3 arguments - * (the element, undefined, and the iterator) and should return a new value. - * @param {THIS=} opt_obj The object to be used as the value of 'this' within - * {@code f}. - * @return {!goog.iter.Iterator<RESULT>} A new iterator that returns the - * results of applying the function to each element in the original - * iterator. - * @template THIS, VALUE, RESULT - */ -goog.iter.map = function(iterable, f, opt_obj) { - var iterator = goog.iter.toIterator(iterable); - var newIter = new goog.iter.Iterator; - newIter.next = function() { - var val = iterator.next(); - return f.call(opt_obj, val, undefined, iterator); - }; - return newIter; -}; - - -/** - * Passes every element of an iterator into a function and accumulates the - * result. - * - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * to iterate over. - * @param {function(this:THIS,VALUE,VALUE):VALUE} f The function to call for - * every element. This function takes 2 arguments (the function's previous - * result or the initial value, and the value of the current element). - * function(previousValue, currentElement) : newValue. - * @param {VALUE} val The initial value to pass into the function on the first - * call. - * @param {THIS=} opt_obj The object to be used as the value of 'this' within - * f. - * @return {VALUE} Result of evaluating f repeatedly across the values of - * the iterator. - * @template THIS, VALUE - */ -goog.iter.reduce = function(iterable, f, val, opt_obj) { - var rval = val; - goog.iter.forEach( - iterable, function(val) { rval = f.call(opt_obj, rval, val); }); - return rval; -}; - - -/** - * Goes through the values in the iterator. Calls f for each of these, and if - * any of them returns true, this returns true (without checking the rest). If - * all return false this will return false. - * - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * object. - * @param { - * function(this:THIS,VALUE,undefined,!goog.iter.Iterator<VALUE>):boolean} f - * The function to call for every value. This function takes 3 arguments - * (the value, undefined, and the iterator) and should return a boolean. - * @param {THIS=} opt_obj The object to be used as the value of 'this' within - * {@code f}. - * @return {boolean} true if any value passes the test. - * @template THIS, VALUE - */ -goog.iter.some = function(iterable, f, opt_obj) { - iterable = goog.iter.toIterator(iterable); - - try { - while (true) { - if (f.call(opt_obj, iterable.next(), undefined, iterable)) { - return true; - } - } - } catch (ex) { - if (ex !== goog.iter.StopIteration) { - throw ex; - } - } - return false; -}; - - -/** - * Goes through the values in the iterator. Calls f for each of these and if any - * of them returns false this returns false (without checking the rest). If all - * return true this will return true. - * - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * object. - * @param { - * function(this:THIS,VALUE,undefined,!goog.iter.Iterator<VALUE>):boolean} f - * The function to call for every value. This function takes 3 arguments - * (the value, undefined, and the iterator) and should return a boolean. - * @param {THIS=} opt_obj The object to be used as the value of 'this' within - * {@code f}. - * @return {boolean} true if every value passes the test. - * @template THIS, VALUE - */ -goog.iter.every = function(iterable, f, opt_obj) { - iterable = goog.iter.toIterator(iterable); - - try { - while (true) { - if (!f.call(opt_obj, iterable.next(), undefined, iterable)) { - return false; - } - } - } catch (ex) { - if (ex !== goog.iter.StopIteration) { - throw ex; - } - } - return true; -}; - - -/** - * Takes zero or more iterables and returns one iterator that will iterate over - * them in the order chained. - * @param {...!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} var_args Any - * number of iterable objects. - * @return {!goog.iter.Iterator<VALUE>} Returns a new iterator that will - * iterate over all the given iterables' contents. - * @template VALUE - */ -goog.iter.chain = function(var_args) { - return goog.iter.chainFromIterable(arguments); -}; - - -/** - * Takes a single iterable containing zero or more iterables and returns one - * iterator that will iterate over each one in the order given. - * @see https://goo.gl/5NRp5d - * @param {goog.iter.Iterable} iterable The iterable of iterables to chain. - * @return {!goog.iter.Iterator<VALUE>} Returns a new iterator that will - * iterate over all the contents of the iterables contained within - * {@code iterable}. - * @template VALUE - */ -goog.iter.chainFromIterable = function(iterable) { - var iterator = goog.iter.toIterator(iterable); - var iter = new goog.iter.Iterator(); - var current = null; - - iter.next = function() { - while (true) { - if (current == null) { - var it = iterator.next(); - current = goog.iter.toIterator(it); - } - try { - return current.next(); - } catch (ex) { - if (ex !== goog.iter.StopIteration) { - throw ex; - } - current = null; - } - } - }; - - return iter; -}; - - -/** - * Builds a new iterator that iterates over the original, but skips elements as - * long as a supplied function returns true. - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * object. - * @param { - * function(this:THIS,VALUE,undefined,!goog.iter.Iterator<VALUE>):boolean} f - * The function to call for every value. This function takes 3 arguments - * (the value, undefined, and the iterator) and should return a boolean. - * @param {THIS=} opt_obj The object to be used as the value of 'this' within - * {@code f}. - * @return {!goog.iter.Iterator<VALUE>} A new iterator that drops elements from - * the original iterator as long as {@code f} is true. - * @template THIS, VALUE - */ -goog.iter.dropWhile = function(iterable, f, opt_obj) { - var iterator = goog.iter.toIterator(iterable); - var newIter = new goog.iter.Iterator; - var dropping = true; - newIter.next = function() { - while (true) { - var val = iterator.next(); - if (dropping && f.call(opt_obj, val, undefined, iterator)) { - continue; - } else { - dropping = false; - } - return val; - } - }; - return newIter; -}; - - -/** - * Builds a new iterator that iterates over the original, but only as long as a - * supplied function returns true. - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * object. - * @param { - * function(this:THIS,VALUE,undefined,!goog.iter.Iterator<VALUE>):boolean} f - * The function to call for every value. This function takes 3 arguments - * (the value, undefined, and the iterator) and should return a boolean. - * @param {THIS=} opt_obj This is used as the 'this' object in f when called. - * @return {!goog.iter.Iterator<VALUE>} A new iterator that keeps elements in - * the original iterator as long as the function is true. - * @template THIS, VALUE - */ -goog.iter.takeWhile = function(iterable, f, opt_obj) { - var iterator = goog.iter.toIterator(iterable); - var iter = new goog.iter.Iterator(); - iter.next = function() { - var val = iterator.next(); - if (f.call(opt_obj, val, undefined, iterator)) { - return val; - } - throw goog.iter.StopIteration; - }; - return iter; -}; - - -/** - * Converts the iterator to an array - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterator - * to convert to an array. - * @return {!Array<VALUE>} An array of the elements the iterator iterates over. - * @template VALUE - */ -goog.iter.toArray = function(iterable) { - // Fast path for array-like. - if (goog.isArrayLike(iterable)) { - return goog.array.toArray(/** @type {!IArrayLike<?>} */ (iterable)); - } - iterable = goog.iter.toIterator(iterable); - var array = []; - goog.iter.forEach(iterable, function(val) { array.push(val); }); - return array; -}; - - -/** - * Iterates over two iterables and returns true if they contain the same - * sequence of elements and have the same length. - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable1 The first - * iterable object. - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable2 The second - * iterable object. - * @param {function(VALUE,VALUE):boolean=} opt_equalsFn Optional comparison - * function. - * Should take two arguments to compare, and return true if the arguments - * are equal. Defaults to {@link goog.array.defaultCompareEquality} which - * compares the elements using the built-in '===' operator. - * @return {boolean} true if the iterables contain the same sequence of elements - * and have the same length. - * @template VALUE - */ -goog.iter.equals = function(iterable1, iterable2, opt_equalsFn) { - var fillValue = {}; - var pairs = goog.iter.zipLongest(fillValue, iterable1, iterable2); - var equalsFn = opt_equalsFn || goog.array.defaultCompareEquality; - return goog.iter.every( - pairs, function(pair) { return equalsFn(pair[0], pair[1]); }); -}; - - -/** - * Advances the iterator to the next position, returning the given default value - * instead of throwing an exception if the iterator has no more entries. - * @param {goog.iter.Iterator<VALUE>|goog.iter.Iterable} iterable The iterable - * object. - * @param {VALUE} defaultValue The value to return if the iterator is empty. - * @return {VALUE} The next item in the iteration, or defaultValue if the - * iterator was empty. - * @template VALUE - */ -goog.iter.nextOrValue = function(iterable, defaultValue) { - try { - return goog.iter.toIterator(iterable).next(); - } catch (e) { - if (e != goog.iter.StopIteration) { - throw e; - } - return defaultValue; - } -}; - - -/** - * Cartesian product of zero or more sets. Gives an iterator that gives every - * combination of one element chosen from each set. For example, - * ([1, 2], [3, 4]) gives ([1, 3], [1, 4], [2, 3], [2, 4]). - * @see http://docs.python.org/library/itertools.html#itertools.product - * @param {...!IArrayLike<VALUE>} var_args Zero or more sets, as - * arrays. - * @return {!goog.iter.Iterator<!Array<VALUE>>} An iterator that gives each - * n-tuple (as an array). - * @template VALUE - */ -goog.iter.product = function(var_args) { - var someArrayEmpty = - goog.array.some(arguments, function(arr) { return !arr.length; }); - - // An empty set in a cartesian product gives an empty set. - if (someArrayEmpty || !arguments.length) { - return new goog.iter.Iterator(); - } - - var iter = new goog.iter.Iterator(); - var arrays = arguments; - - // The first indices are [0, 0, ...] - var indicies = goog.array.repeat(0, arrays.length); - - iter.next = function() { - - if (indicies) { - var retVal = goog.array.map(indicies, function(valueIndex, arrayIndex) { - return arrays[arrayIndex][valueIndex]; - }); - - // Generate the next-largest indices for the next call. - // Increase the rightmost index. If it goes over, increase the next - // rightmost (like carry-over addition). - for (var i = indicies.length - 1; i >= 0; i--) { - // Assertion prevents compiler warning below. - goog.asserts.assert(indicies); - if (indicies[i] < arrays[i].length - 1) { - indicies[i]++; - break; - } - - // We're at the last indices (the last element of every array), so - // the iteration is over on the next call. - if (i == 0) { - indicies = null; - break; - } - // Reset the index in this column and loop back to increment the - // next one. - indicies[i] = 0; - } - return retVal; - } - - throw goog.iter.StopIteration; - }; - - return iter; -}; - - -/** - * Create an iterator to cycle over the iterable's elements indefinitely. - * For example, ([1, 2, 3]) would return : 1, 2, 3, 1, 2, 3, ... - * @see: http://docs.python.org/library/itertools.html#itertools.cycle. - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable object. - * @return {!goog.iter.Iterator<VALUE>} An iterator that iterates indefinitely - * over the values in {@code iterable}. - * @template VALUE - */ -goog.iter.cycle = function(iterable) { - var baseIterator = goog.iter.toIterator(iterable); - - // We maintain a cache to store the iterable elements as we iterate - // over them. The cache is used to return elements once we have - // iterated over the iterable once. - var cache = []; - var cacheIndex = 0; - - var iter = new goog.iter.Iterator(); - - // This flag is set after the iterable is iterated over once - var useCache = false; - - iter.next = function() { - var returnElement = null; - - // Pull elements off the original iterator if not using cache - if (!useCache) { - try { - // Return the element from the iterable - returnElement = baseIterator.next(); - cache.push(returnElement); - return returnElement; - } catch (e) { - // If an exception other than StopIteration is thrown - // or if there are no elements to iterate over (the iterable was empty) - // throw an exception - if (e != goog.iter.StopIteration || goog.array.isEmpty(cache)) { - throw e; - } - // set useCache to true after we know that a 'StopIteration' exception - // was thrown and the cache is not empty (to handle the 'empty iterable' - // use case) - useCache = true; - } - } - - returnElement = cache[cacheIndex]; - cacheIndex = (cacheIndex + 1) % cache.length; - - return returnElement; - }; - - return iter; -}; - - -/** - * Creates an iterator that counts indefinitely from a starting value. - * @see http://docs.python.org/2/library/itertools.html#itertools.count - * @param {number=} opt_start The starting value. Default is 0. - * @param {number=} opt_step The number to increment with between each call to - * next. Negative and floating point numbers are allowed. Default is 1. - * @return {!goog.iter.Iterator<number>} A new iterator that returns the values - * in the series. - */ -goog.iter.count = function(opt_start, opt_step) { - var counter = opt_start || 0; - var step = goog.isDef(opt_step) ? opt_step : 1; - var iter = new goog.iter.Iterator(); - - iter.next = function() { - var returnValue = counter; - counter += step; - return returnValue; - }; - - return iter; -}; - - -/** - * Creates an iterator that returns the same object or value repeatedly. - * @param {VALUE} value Any object or value to repeat. - * @return {!goog.iter.Iterator<VALUE>} A new iterator that returns the - * repeated value. - * @template VALUE - */ -goog.iter.repeat = function(value) { - var iter = new goog.iter.Iterator(); - - iter.next = goog.functions.constant(value); - - return iter; -}; - - -/** - * Creates an iterator that returns running totals from the numbers in - * {@code iterable}. For example, the array {@code [1, 2, 3, 4, 5]} yields - * {@code 1 -> 3 -> 6 -> 10 -> 15}. - * @see http://docs.python.org/3.2/library/itertools.html#itertools.accumulate - * @param {!goog.iter.Iterable} iterable The iterable of numbers to - * accumulate. - * @return {!goog.iter.Iterator<number>} A new iterator that returns the - * numbers in the series. - */ -goog.iter.accumulate = function(iterable) { - var iterator = goog.iter.toIterator(iterable); - var total = 0; - var iter = new goog.iter.Iterator(); - - iter.next = function() { - total += iterator.next(); - return total; - }; - - return iter; -}; - - -/** - * Creates an iterator that returns arrays containing the ith elements from the - * provided iterables. The returned arrays will be the same size as the number - * of iterables given in {@code var_args}. Once the shortest iterable is - * exhausted, subsequent calls to {@code next()} will throw - * {@code goog.iter.StopIteration}. - * @see http://docs.python.org/2/library/itertools.html#itertools.izip - * @param {...!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} var_args Any - * number of iterable objects. - * @return {!goog.iter.Iterator<!Array<VALUE>>} A new iterator that returns - * arrays of elements from the provided iterables. - * @template VALUE - */ -goog.iter.zip = function(var_args) { - var args = arguments; - var iter = new goog.iter.Iterator(); - - if (args.length > 0) { - var iterators = goog.array.map(args, goog.iter.toIterator); - iter.next = function() { - var arr = goog.array.map(iterators, function(it) { return it.next(); }); - return arr; - }; - } - - return iter; -}; - - -/** - * Creates an iterator that returns arrays containing the ith elements from the - * provided iterables. The returned arrays will be the same size as the number - * of iterables given in {@code var_args}. Shorter iterables will be extended - * with {@code fillValue}. Once the longest iterable is exhausted, subsequent - * calls to {@code next()} will throw {@code goog.iter.StopIteration}. - * @see http://docs.python.org/2/library/itertools.html#itertools.izip_longest - * @param {VALUE} fillValue The object or value used to fill shorter iterables. - * @param {...!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} var_args Any - * number of iterable objects. - * @return {!goog.iter.Iterator<!Array<VALUE>>} A new iterator that returns - * arrays of elements from the provided iterables. - * @template VALUE - */ -goog.iter.zipLongest = function(fillValue, var_args) { - var args = goog.array.slice(arguments, 1); - var iter = new goog.iter.Iterator(); - - if (args.length > 0) { - var iterators = goog.array.map(args, goog.iter.toIterator); - - iter.next = function() { - var iteratorsHaveValues = false; // false when all iterators are empty. - var arr = goog.array.map(iterators, function(it) { - var returnValue; - try { - returnValue = it.next(); - // Iterator had a value, so we've not exhausted the iterators. - // Set flag accordingly. - iteratorsHaveValues = true; - } catch (ex) { - if (ex !== goog.iter.StopIteration) { - throw ex; - } - returnValue = fillValue; - } - return returnValue; - }); - - if (!iteratorsHaveValues) { - throw goog.iter.StopIteration; - } - return arr; - }; - } - - return iter; -}; - - -/** - * Creates an iterator that filters {@code iterable} based on a series of - * {@code selectors}. On each call to {@code next()}, one item is taken from - * both the {@code iterable} and {@code selectors} iterators. If the item from - * {@code selectors} evaluates to true, the item from {@code iterable} is given. - * Otherwise, it is skipped. Once either {@code iterable} or {@code selectors} - * is exhausted, subsequent calls to {@code next()} will throw - * {@code goog.iter.StopIteration}. - * @see http://docs.python.org/2/library/itertools.html#itertools.compress - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable to filter. - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} selectors An - * iterable of items to be evaluated in a boolean context to determine if - * the corresponding element in {@code iterable} should be included in the - * result. - * @return {!goog.iter.Iterator<VALUE>} A new iterator that returns the - * filtered values. - * @template VALUE - */ -goog.iter.compress = function(iterable, selectors) { - var selectorIterator = goog.iter.toIterator(selectors); - - return goog.iter.filter( - iterable, function() { return !!selectorIterator.next(); }); -}; - - - -/** - * Implements the {@code goog.iter.groupBy} iterator. - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable to group. - * @param {function(VALUE): KEY=} opt_keyFunc Optional function for - * determining the key value for each group in the {@code iterable}. Default - * is the identity function. - * @constructor - * @extends {goog.iter.Iterator<!Array<?>>} - * @template KEY, VALUE - * @private - */ -goog.iter.GroupByIterator_ = function(iterable, opt_keyFunc) { - - /** - * The iterable to group, coerced to an iterator. - * @type {!goog.iter.Iterator} - */ - this.iterator = goog.iter.toIterator(iterable); - - /** - * A function for determining the key value for each element in the iterable. - * If no function is provided, the identity function is used and returns the - * element unchanged. - * @type {function(VALUE): KEY} - */ - this.keyFunc = opt_keyFunc || goog.functions.identity; - - /** - * The target key for determining the start of a group. - * @type {KEY} - */ - this.targetKey; - - /** - * The current key visited during iteration. - * @type {KEY} - */ - this.currentKey; - - /** - * The current value being added to the group. - * @type {VALUE} - */ - this.currentValue; -}; -goog.inherits(goog.iter.GroupByIterator_, goog.iter.Iterator); - - -/** @override */ -goog.iter.GroupByIterator_.prototype.next = function() { - while (this.currentKey == this.targetKey) { - this.currentValue = this.iterator.next(); // Exits on StopIteration - this.currentKey = this.keyFunc(this.currentValue); - } - this.targetKey = this.currentKey; - return [this.currentKey, this.groupItems_(this.targetKey)]; -}; - - -/** - * Performs the grouping of objects using the given key. - * @param {KEY} targetKey The target key object for the group. - * @return {!Array<VALUE>} An array of grouped objects. - * @private - */ -goog.iter.GroupByIterator_.prototype.groupItems_ = function(targetKey) { - var arr = []; - while (this.currentKey == targetKey) { - arr.push(this.currentValue); - try { - this.currentValue = this.iterator.next(); - } catch (ex) { - if (ex !== goog.iter.StopIteration) { - throw ex; - } - break; - } - this.currentKey = this.keyFunc(this.currentValue); - } - return arr; -}; - - -/** - * Creates an iterator that returns arrays containing elements from the - * {@code iterable} grouped by a key value. For iterables with repeated - * elements (i.e. sorted according to a particular key function), this function - * has a {@code uniq}-like effect. For example, grouping the array: - * {@code [A, B, B, C, C, A]} produces - * {@code [A, [A]], [B, [B, B]], [C, [C, C]], [A, [A]]}. - * @see http://docs.python.org/2/library/itertools.html#itertools.groupby - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable to group. - * @param {function(VALUE): KEY=} opt_keyFunc Optional function for - * determining the key value for each group in the {@code iterable}. Default - * is the identity function. - * @return {!goog.iter.Iterator<!Array<?>>} A new iterator that returns - * arrays of consecutive key and groups. - * @template KEY, VALUE - */ -goog.iter.groupBy = function(iterable, opt_keyFunc) { - return new goog.iter.GroupByIterator_(iterable, opt_keyFunc); -}; - - -/** - * Gives an iterator that gives the result of calling the given function - * <code>f</code> with the arguments taken from the next element from - * <code>iterable</code> (the elements are expected to also be iterables). - * - * Similar to {@see goog.iter#map} but allows the function to accept multiple - * arguments from the iterable. - * - * @param {!goog.iter.Iterable} iterable The iterable of - * iterables to iterate over. - * @param {function(this:THIS,...*):RESULT} f The function to call for every - * element. This function takes N+2 arguments, where N represents the - * number of items from the next element of the iterable. The two - * additional arguments passed to the function are undefined and the - * iterator itself. The function should return a new value. - * @param {THIS=} opt_obj The object to be used as the value of 'this' within - * {@code f}. - * @return {!goog.iter.Iterator<RESULT>} A new iterator that returns the - * results of applying the function to each element in the original - * iterator. - * @template THIS, RESULT - */ -goog.iter.starMap = function(iterable, f, opt_obj) { - var iterator = goog.iter.toIterator(iterable); - var iter = new goog.iter.Iterator(); - - iter.next = function() { - var args = goog.iter.toArray(iterator.next()); - return f.apply(opt_obj, goog.array.concat(args, undefined, iterator)); - }; - - return iter; -}; - - -/** - * Returns an array of iterators each of which can iterate over the values in - * {@code iterable} without advancing the others. - * @see http://docs.python.org/2/library/itertools.html#itertools.tee - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable to tee. - * @param {number=} opt_num The number of iterators to create. Default is 2. - * @return {!Array<goog.iter.Iterator<VALUE>>} An array of iterators. - * @template VALUE - */ -goog.iter.tee = function(iterable, opt_num) { - var iterator = goog.iter.toIterator(iterable); - var num = goog.isNumber(opt_num) ? opt_num : 2; - var buffers = - goog.array.map(goog.array.range(num), function() { return []; }); - - var addNextIteratorValueToBuffers = function() { - var val = iterator.next(); - goog.array.forEach(buffers, function(buffer) { buffer.push(val); }); - }; - - var createIterator = function(buffer) { - // Each tee'd iterator has an associated buffer (initially empty). When a - // tee'd iterator's buffer is empty, it calls - // addNextIteratorValueToBuffers(), adding the next value to all tee'd - // iterators' buffers, and then returns that value. This allows each - // iterator to be advanced independently. - var iter = new goog.iter.Iterator(); - - iter.next = function() { - if (goog.array.isEmpty(buffer)) { - addNextIteratorValueToBuffers(); - } - goog.asserts.assert(!goog.array.isEmpty(buffer)); - return buffer.shift(); - }; - - return iter; - }; - - return goog.array.map(buffers, createIterator); -}; - - -/** - * Creates an iterator that returns arrays containing a count and an element - * obtained from the given {@code iterable}. - * @see http://docs.python.org/2/library/functions.html#enumerate - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable to enumerate. - * @param {number=} opt_start Optional starting value. Default is 0. - * @return {!goog.iter.Iterator<!Array<?>>} A new iterator containing - * count/item pairs. - * @template VALUE - */ -goog.iter.enumerate = function(iterable, opt_start) { - return goog.iter.zip(goog.iter.count(opt_start), iterable); -}; - - -/** - * Creates an iterator that returns the first {@code limitSize} elements from an - * iterable. If this number is greater than the number of elements in the - * iterable, all the elements are returned. - * @see http://goo.gl/V0sihp Inspired by the limit iterator in Guava. - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable to limit. - * @param {number} limitSize The maximum number of elements to return. - * @return {!goog.iter.Iterator<VALUE>} A new iterator containing - * {@code limitSize} elements. - * @template VALUE - */ -goog.iter.limit = function(iterable, limitSize) { - goog.asserts.assert(goog.math.isInt(limitSize) && limitSize >= 0); - - var iterator = goog.iter.toIterator(iterable); - - var iter = new goog.iter.Iterator(); - var remaining = limitSize; - - iter.next = function() { - if (remaining-- > 0) { - return iterator.next(); - } - throw goog.iter.StopIteration; - }; - - return iter; -}; - - -/** - * Creates an iterator that is advanced {@code count} steps ahead. Consumed - * values are silently discarded. If {@code count} is greater than the number - * of elements in {@code iterable}, an empty iterator is returned. Subsequent - * calls to {@code next()} will throw {@code goog.iter.StopIteration}. - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable to consume. - * @param {number} count The number of elements to consume from the iterator. - * @return {!goog.iter.Iterator<VALUE>} An iterator advanced zero or more steps - * ahead. - * @template VALUE - */ -goog.iter.consume = function(iterable, count) { - goog.asserts.assert(goog.math.isInt(count) && count >= 0); - - var iterator = goog.iter.toIterator(iterable); - - while (count-- > 0) { - goog.iter.nextOrValue(iterator, null); - } - - return iterator; -}; - - -/** - * Creates an iterator that returns a range of elements from an iterable. - * Similar to {@see goog.array#slice} but does not support negative indexes. - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable to slice. - * @param {number} start The index of the first element to return. - * @param {number=} opt_end The index after the last element to return. If - * defined, must be greater than or equal to {@code start}. - * @return {!goog.iter.Iterator<VALUE>} A new iterator containing a slice of - * the original. - * @template VALUE - */ -goog.iter.slice = function(iterable, start, opt_end) { - goog.asserts.assert(goog.math.isInt(start) && start >= 0); - - var iterator = goog.iter.consume(iterable, start); - - if (goog.isNumber(opt_end)) { - goog.asserts.assert(goog.math.isInt(opt_end) && opt_end >= start); - iterator = goog.iter.limit(iterator, opt_end - start /* limitSize */); - } - - return iterator; -}; - - -/** - * Checks an array for duplicate elements. - * @param {?IArrayLike<VALUE>} arr The array to check for - * duplicates. - * @return {boolean} True, if the array contains duplicates, false otherwise. - * @private - * @template VALUE - */ -// TODO(user): Consider moving this into goog.array as a public function. -goog.iter.hasDuplicates_ = function(arr) { - var deduped = []; - goog.array.removeDuplicates(arr, deduped); - return arr.length != deduped.length; -}; - - -/** - * Creates an iterator that returns permutations of elements in - * {@code iterable}. - * - * Permutations are obtained by taking the Cartesian product of - * {@code opt_length} iterables and filtering out those with repeated - * elements. For example, the permutations of {@code [1,2,3]} are - * {@code [[1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1]]}. - * @see http://docs.python.org/2/library/itertools.html#itertools.permutations - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable from which to generate permutations. - * @param {number=} opt_length Length of each permutation. If omitted, defaults - * to the length of {@code iterable}. - * @return {!goog.iter.Iterator<!Array<VALUE>>} A new iterator containing the - * permutations of {@code iterable}. - * @template VALUE - */ -goog.iter.permutations = function(iterable, opt_length) { - var elements = goog.iter.toArray(iterable); - var length = goog.isNumber(opt_length) ? opt_length : elements.length; - - var sets = goog.array.repeat(elements, length); - var product = goog.iter.product.apply(undefined, sets); - - return goog.iter.filter( - product, function(arr) { return !goog.iter.hasDuplicates_(arr); }); -}; - - -/** - * Creates an iterator that returns combinations of elements from - * {@code iterable}. - * - * Combinations are obtained by taking the {@see goog.iter#permutations} of - * {@code iterable} and filtering those whose elements appear in the order they - * are encountered in {@code iterable}. For example, the 3-length combinations - * of {@code [0,1,2,3]} are {@code [[0,1,2], [0,1,3], [0,2,3], [1,2,3]]}. - * @see http://docs.python.org/2/library/itertools.html#itertools.combinations - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable from which to generate combinations. - * @param {number} length The length of each combination. - * @return {!goog.iter.Iterator<!Array<VALUE>>} A new iterator containing - * combinations from the {@code iterable}. - * @template VALUE - */ -goog.iter.combinations = function(iterable, length) { - var elements = goog.iter.toArray(iterable); - var indexes = goog.iter.range(elements.length); - var indexIterator = goog.iter.permutations(indexes, length); - // sortedIndexIterator will now give arrays of with the given length that - // indicate what indexes into "elements" should be returned on each iteration. - var sortedIndexIterator = goog.iter.filter( - indexIterator, function(arr) { return goog.array.isSorted(arr); }); - - var iter = new goog.iter.Iterator(); - - function getIndexFromElements(index) { return elements[index]; } - - iter.next = function() { - return goog.array.map(sortedIndexIterator.next(), getIndexFromElements); - }; - - return iter; -}; - - -/** - * Creates an iterator that returns combinations of elements from - * {@code iterable}, with repeated elements possible. - * - * Combinations are obtained by taking the Cartesian product of {@code length} - * iterables and filtering those whose elements appear in the order they are - * encountered in {@code iterable}. For example, the 2-length combinations of - * {@code [1,2,3]} are {@code [[1,1], [1,2], [1,3], [2,2], [2,3], [3,3]]}. - * @see https://goo.gl/C0yXe4 - * @see https://goo.gl/djOCsk - * @param {!goog.iter.Iterator<VALUE>|!goog.iter.Iterable} iterable The - * iterable to combine. - * @param {number} length The length of each combination. - * @return {!goog.iter.Iterator<!Array<VALUE>>} A new iterator containing - * combinations from the {@code iterable}. - * @template VALUE - */ -goog.iter.combinationsWithReplacement = function(iterable, length) { - var elements = goog.iter.toArray(iterable); - var indexes = goog.array.range(elements.length); - var sets = goog.array.repeat(indexes, length); - var indexIterator = goog.iter.product.apply(undefined, sets); - // sortedIndexIterator will now give arrays of with the given length that - // indicate what indexes into "elements" should be returned on each iteration. - var sortedIndexIterator = goog.iter.filter( - indexIterator, function(arr) { return goog.array.isSorted(arr); }); - - var iter = new goog.iter.Iterator(); - - function getIndexFromElements(index) { return elements[index]; } - - iter.next = function() { - return goog.array.map( - /** @type {!Array<number>} */ - (sortedIndexIterator.next()), getIndexFromElements); - }; - - return iter; -}; |